1. Field of the Invention
The present invention relates to a target object detection server for detecting a target object, more specifically, relates to a target object detection server which can increase the reliability for detecting the target object.
2. Description of Related Art
In recent years, a target object detection system has been developed. A conventional target object detection system detects a target object existing in a surrounding area of a detection apparatus by using a tag (for example, RFID) mounted on the target object. An apparatus in a Japanese Patent Laid-Open Application No. 2005-288554 discloses an example of these conventional apparatuses. The conventional target object detection system detects a presence of a target object by means of a detection apparatus. In this system, the detection apparatus periodically transmits a radio wave at a short interval, and the transmitted radio wave is received by a tag. Then, the tag which receives the transmitted radio wave transmits a radio wave at the same frequency as the received radio wave. Accordingly, by detecting the radio wave transmitted from the tag, the detection apparatus detects the presence of the target object.
Here, in some cases of these conventional target object detection systems, the target object is a person while the detection apparatus is a mobile robot. In this occasion, when the mobile robot detects a person, the mobile robot executes some motion (greeting or guide) for the detected person.
However, a communication system using a radio wave transmitted from the tag mounted on the target object tends to be affected by a surrounding environment. In some occasions, radio wave communication becomes so unstable as not to communicate effectively. For example, if the radio wave transmitted from the tag can not be detected by the detection apparatus, the detection apparatus can not detect the tag mounted on the target object. Therefore, with such a detection failure, eventually decreases the reliability for detecting the target object.
Additionally, if the number of target objects increases, this increases computational loads of a mobile robot. As a result, the same detection defect arises, which decreases the reliability for detecting the target object.
Therefore, it is an object of the present invention to provide a target object detection server which is capable of increasing the reliability for detecting a target object by addressing the detection defect as mentioned above.